Festivals form an essential aspect of the socio-cultural life of the people of the state. As a matter of fact, festivals are the mirror of the people's culture. Since agriculture is the mainstay of the population , naturally, the festivals celebrated by the people are closely connected with their occupation. Such festivals are celebrated at a larger sale for thanking the Gods for their providence and for saying a prayer a prayer for a bumper crop. Throughout the year festivals are celebrated by some tribe or the other. Some of the important festivals are Solung, Mopin, Losar, Boori Boot, Dree, Nechi Dau, Khan, Kshyat-Sowai, Loku, Longte Yullo, Mol, Nyokum, Ojiale, Reh, Sanken, Si-Donyi and Tamladu.

Animal sacrifices are a common ritual in most of the festivals, particularly in the non-Bodic tribes. The festivals have been firmly blended with the lifestyle of the people of Arunachal Pradesh. For some communities like the Mijis these are occasions to bring all people together who might otherwise be scattered in far flung villages. This serves as a reminder of the richness of their cultural heritage.

The spring time festivals are celebrated during the period from January to April by the different groups. In the celebration of these festivals, the religious rites and the sacrifices are generally performed by their priests assisted by some select male members.

The Losar festival of the Monpas, which is their new year, is celebrated for five days. On the eve of the festival people clean out their homes to usher in the new year and to discard the old. The dirt and the grit of the old year is considered to symbolise ill health. During the five days of the festivities prayers are offered for prosperity and good health; the festivities include the hoisting of religious flags atop their homes; visits to he homes of friends and relatives; oly uddhist sriptures are read in ervery home and butter lamps are lit in houses and the campuses.

Appeasement of the dieties who conrol the peace and prosperity of the people is the thought behind the six day celebrations of the Reh festival, essentially associated with the Idu Mishmis. The festival comes to an end with great fanfare and the priest dance performed during the six days is its speial attraction.

The Wanhos celebrate their most popular estival, Ojiyale during March-April, for a period of six to twelve days interspersed with prayer, song and dance. Villagers exchange bamboo tubes of rice beeras a mark of greeting and good will. Pig's skin is offered to the village chief as a mark of respect.

Another important festival is Tamladu, essentially celebrated by the Digaru Mishmis tribe. During the festival, prayers are offered to the God of Earth and the God of Water for protection against natural calamities. The supreme- Lord Jebmalu, is worshipped and welfare of human beings, the standing crops and domestic animals.

Another is the Khan festival, an occasion for the reunion of the people. Besides the usual festivities, the significance of the festival lies in the ceremony whereby the priest ties a piece of wool around everybody's neck. The belief is that the enchanted thread will bring good luck to each of them.

Sangken festival, is an occasion to bathe the images of Lord Buddha ceremoniously. Thsi also heralds the new year and people sprinkle water on each other as a sign of merriment. One of the groups celebrate Mopin for wealth, prosperity, good health and universal happiness. Smearing of rice powder on each others' faces marks the beginning of the festival which is celebrated for five days. The Mol festival of the Tangsas is also celebrated for three days to welcome the new year.